/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * --------------
 * XYDataset.java
 * --------------
 * (C) Copyright 2000-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes (from 18-Sep-2001)
 * --------------------------
 * 18-Sep-2001 : Added standard header and fixed DOS encoding problem (DG);
 * 15-Oct-2001 : Moved to a new package (com.jrefinery.data.*) (DG);
 * 22-Oct-2001 : Renamed DataSource.java --> Dataset.java etc. (DG);
 * 17-Nov-2001 : Now extends SeriesDataset (DG);
 * 15-Jul-2004 : Switched getX() with getXValue() and getY() with
 *               getYValue() (DG);
 * 29-Jul-2004 : Added getDomainOrder() method (DG);
 * 18-Aug-2004 : Moved from org.jfree.data --> org.jfree.data.xy (DG);
 *
 */

package net.droidsolutions.droidcharts.core.data;

import net.droidsolutions.droidcharts.core.data.general.SeriesDataset;

/**
 * An interface through which data in the form of (x, y) items can be accessed.
 */
public interface XYDataset extends SeriesDataset {

	/**
	 * Returns the order of the domain (or X) values returned by the dataset.
	 * 
	 * @return The order (never <code>null</code>).
	 */
	public DomainOrder getDomainOrder();

	/**
	 * Returns the number of items in a series. <br>
	 * <br>
	 * It is recommended that classes that implement this method should throw an
	 * <code>IllegalArgumentException</code> if the <code>series</code> argument
	 * is outside the specified range.
	 * 
	 * @param series
	 *            the series index (in the range <code>0</code> to
	 *            <code>getSeriesCount() - 1</code>).
	 * 
	 * @return The item count.
	 */
	public int getItemCount(int series);

	/**
	 * Returns the x-value for an item within a series. The x-values may or may
	 * not be returned in ascending order, that is up to the class implementing
	 * the interface.
	 * 
	 * @param series
	 *            the series index (in the range <code>0</code> to
	 *            <code>getSeriesCount() - 1</code>).
	 * @param item
	 *            the item index (in the range <code>0</code> to
	 *            <code>getItemCount(series)</code>).
	 * 
	 * @return The x-value (never <code>null</code>).
	 */
	public Number getX(int series, int item);

	/**
	 * Returns the x-value for an item within a series.
	 * 
	 * @param series
	 *            the series index (in the range <code>0</code> to
	 *            <code>getSeriesCount() - 1</code>).
	 * @param item
	 *            the item index (in the range <code>0</code> to
	 *            <code>getItemCount(series)</code>).
	 * 
	 * @return The x-value.
	 */
	public double getXValue(int series, int item);

	/**
	 * Returns the y-value for an item within a series.
	 * 
	 * @param series
	 *            the series index (in the range <code>0</code> to
	 *            <code>getSeriesCount() - 1</code>).
	 * @param item
	 *            the item index (in the range <code>0</code> to
	 *            <code>getItemCount(series)</code>).
	 * 
	 * @return The y-value (possibly <code>null</code>).
	 */
	public Number getY(int series, int item);

	/**
	 * Returns the y-value (as a double primitive) for an item within a series.
	 * 
	 * @param series
	 *            the series index (in the range <code>0</code> to
	 *            <code>getSeriesCount() - 1</code>).
	 * @param item
	 *            the item index (in the range <code>0</code> to
	 *            <code>getItemCount(series)</code>).
	 * 
	 * @return The y-value.
	 */
	public double getYValue(int series, int item);

}
